It is known to use a reciprocating pump for the pumping of a liquid in a delivery system. Such reciprocating pumps do not have a smooth output and a pressure drop occurs in the liquid during the reversal of the pump stroke. Surge suppression. apparatus is used to negate the drop in pressure and thereby improve the constancy of the liquid output pressure.
A known surge suppression apparatus comprises a passive surge bottle which is basically a captive (static) gas volume acting as a pressure reservoir. A passive surge bottle inevitably loses pressure in use and thus there is a necessity for the periodic recharging of the bottle with compressed gas and the subsequent, associated recalibration of the system utilising the bottle. European Patent Application No. EP 0 707 173 A1 discloses a surge suppression apparatus incorporating an active pressure regulation arrangement which recharges the gas pressure therein automatically. Such an active pressure regulation arrangement in a surge suppressor removes the necessity for the periodic recharging of a passive surge bottle, but the apparatus disclosed in EP 0 707 173 A1 tends to be bulky and inconvenient in use. It is an object of the present invention to provide a surge suppression apparatus in an improved and simplified form.